#include<stdio.h>
#include<string.h>

int main()
{
	char a[100],b[100];
	int i,n,t,flag;
	while (1)
	{
		flag=1;
		i=0;
		while ((a[i]=getchar())!='\n')
			if ((a[i]>=48&&a[i]<=57)||(a[i]>=65&&a[i]<=90)||(a[i]>=97&&a[i]<=122))
				i++;
			else
				flag=0;
		if (flag==0)
		{
			printf("Input Error\n");
			continue;
		}
		a[i]=0;
		b[i]=0;
		i=i-1;
		t=i;
		if (strcmp(a,"exit")==0)
		{
			printf("End Of Input\n");
			break;
		}
		for (;i>=0;i--)
			b[i]=a[t-i];
		if (strcmp(a,b)==0)
			printf("Yes\n");
		else
			printf("No\n");
	}
	return 0;
}
